Method for updating carrier information in a broadband wireless access system

ABSTRACT

The present invention relates to a broadband wireless access system, and more particularly, to a method in which a terminal acquires and updates global carrier configuration information of base stations in a network, and to an apparatus for performing the method. According to one embodiment of the present invention, a method in which a terminal acquires carrier configuration information in a broadband wireless access system that supports multiple carriers comprises the following steps; transmitting a first message containing a change count value of the carrier configuration information acquired by the terminal: receiving, from the base station and in response to the first message, a second message containing the current change count value of the carrier configuration information; and, if the change count value of the first message and the change count value of the second message are different from each other, receiving a third message containing current carrier configuration information and the current change count value from the base station.

TECHNICAL FIELD

The present invention relates to a broadband wireless access system, andmore particularly, to a method for a mobile station to acquire andupdate global carrier configuration information of base stations in anetwork and apparatus therefor.

BACKGROUND ART

In the following description, carriers are schematically explained.

First of all, a user is able to provide information to transmit bymodulating and manipulating an amplitude, frequency and/or phase of asinusoidal wave or a periodic pulse wave. In this case, the sinusoidalor periodic pulse wave playing a role in carrying the information iscalled a carrier.

Carrier modulation schemes may be classified into a single-carriermodulation (SCM) scheme and a multicarrier modulation (MCM) scheme. Inparticular, the single-carrier modulation (SCM) scheme is a modulationscheme of having all information carried on a single carrier.

According to the multicarrier modulation (MCM) scheme, a whole bandwidthchannel of a single carrier is divided into a plurality of subchannelshaving small bandwidths and a plurality of narrowband subcarriers aretransmitted on the subchannels by multiplexing.

In doing so, if the multicarrier modulation (MCM) scheme is used, aplurality of the subchannels may be approximated to a flat channel owingto their small bandwidths. And, a user may be able to compensate forchannel distortion using a simple equalizer. Moreover, the multicarriermodulation (MCM) scheme enables fast implementation using Fast FourierTransform (FFT). In particular, the multicarrier modulation (MCM) schemeis superior to the single-carrier modulation (SCM) scheme in aspect offast data transmission.

As the performance of a base station and/or a mobile station is beingincreasingly enhanced, a frequency bandwidth providable or available forthe base station and/or the mobile station is extending increasingly.Hence, according to embodiments of the present invention, a multicarriersystem supportive of a broadband in a manner of aggregating at least oneor more carriers together is disclosed.

In particular, a multicarrier system mentioned in the followingdescription corresponds to a case of aggregating t least one or morecarriers to use, which is different from the multicarrier modulation(MCM) scheme of viding a single carrier to use.

In order to efficiently use multi-band or multicarrier, a scheme for asingle medium access control (MAC) entity to manage several carriers(e.g., several frequency carriers (FCs)) has been proposed.

FIG. 1( a) and FIG. 1( b) are diagrams to describe a multi-band radiofrequency (RF) based signal transceiving method.

Referring to FIG. 1, a medium access control (MAC) layer in atransmitting/receiver may be able to manage a plurality of carriers toefficiently use multiple carriers. In doing so, in order to effectivelytransceive multiple carriers, assume that both of the transmitter andthe receiver are capable of transceiving the multiple carriers. In thiscase, since it is unnecessary for frequency carriers (FCs) managed bythe MAC layer to be contiguous with each other, it is flexible in aspectof resource management. In particular, both contiguous carrieraggregation and non-contiguous carrier aggregation are possible.

Referring to FIG. 1( a) and FIG. 1( b), physical layers PHY 0 to PHY n−1indicate multiple bands of the present invention, respectively. Each ofthe multiple bands may have a frequency carrier (FC) size assigned to aspecific service by a previously determined frequency policy. Forinstance, PHY 0 (RF carrier 0) may have a size of a frequency bandassigned for a normal FM radio broadcast and PHY 1 (RF carrier 1) mayhave a size of a frequency band assigned for a mobile phonecommunication.

Thus, the respective frequency bands may differ from each other infrequency band size in accordance with frequency band properties,respectively. For clarity, in the following description, assume thateach frequency carrier (FC) has a size of A MHz. And, each of thefrequency assignment brands may be represented as a carrier frequency touse a baseband signal on a corresponding frequency band. In thefollowing description, each frequency assignment band shall be named acarrier frequency band. If here is no confusion, each carrier frequencyband shall be simply named a carrier. Moreover, as recently defined in3GPP LTE-A, the above-mentioned carrier may be called a componentcarrier to be discriminated from a subcarrier used by a multicarriersystem.

In this aspect, the multi-band scheme may be called a multicarrierscheme or a carrier aggregation scheme.

FIG. 2 a diagram for one example of illustrating how multiple carriersare used in a general wireless communication system.

Referring to FIG. 2, a multicarrier in a general technology may includecontiguous carrier aggregation [FIG. 2( a)] or non-contiguous carrieraggregation [FIG. 2( b)]. In this case, a unit of the carrieraggregation is a basic bandwidth unit of a general legacy system (e.g.,LTE in case of LTE-A (long term evolution-advanced) system, IEEE 802.16ein case of IEEE 802.16m system). In a multicarrier configuration of ageneral technology, carriers of two types are defined as follows.

First of all, a 1^(st) carrier (or, a primary carrier) means a carriermeans a carrier for exchanging traffics and full PHY/MAC controlinformations between a mobile station and a base station. And, theprimary carrier may be usable for such a general operation of a mobilestation as a network entry and the like. Moreover, each mobile stationhas one primary carrier in one cell.

Secondly, a 2^(nd) carrier (or, a secondary carrier) generally means asupplementary carrier usable for an exchange of traffics in accordancewith a UE-specific assignment command and rule received on the 1^(st)carrier. The 2^(nd) carrier may include control signaling to support amulticarrier operation. Generally, all control informations andinformation on a secondary information are received via a primarycarrier and data is transmitted and received on the secondary carrier.

General technology may be able to categorize carriers of a multicarriersystem into a fully configured carrier and a partially configuredcarrier based on the above-described primary and secondary carriers.

First of all, the fully configured carrier may indicate the carrier forconfiguring all control signals including synchronization, broadcast,multicast and unicast control channels. Moreover, informations andparameters for carriers different from those of the multicarrieroperation may be included in the control channels.

Secondly, the partially configured carrier may mean the carrier forconfiguring all control channels to support a DL transmission in a DLcarrier having no UL carrier to pair in a TDD (time division duplex) DLtransmission or FDD (frequency division duplex) mode. A secondarycarrier, which is a fully configured carrier configured in a prescribedmobile station may be allocated as a primary carrier of another mobilestation.

Generally, a mobile station performs an initial network entry via aprimary carrier and may be able to exchange information on mutualmulticarrier capability in a registration procedure via registrationrequest/response (AAI_REG-REQ/RSP) exchange with a base station.

There are various kinds of methods for obtaining multicarrierconfiguration information of a specific base station. For example, MCinformation of a specific base station is broadcasted or may betransmitted by unicast per mobile station. For another example, carriersused by base stations within a corresponding network are categorized bygroups, MC informations of groups are entirely provided to a mobilestation, and a group combination of the MC informations applied to thecorresponding base station is notified to the corresponding mobilestation.

In case that the information on the multicarrier configuration istransmitted in a manner of the latter case, the correspondinginformation contains the informations of a plurality of MC groupsentirely. However, it is inefficient for a mobile station to receive theinformation on the multicarrier configuration each time performing anetwork reentry.

DISCLOSURE OF THE INVENTION Technical Task

Accordingly, the present invention is directed to substantially obviateone or more problems due to limitations and disadvantages of the relatedart. First of all, an object of the present invention is to provide amethod for a mobile station to efficiently obtain broadband carrierconfiguration information from a base station in a multicarrierenvironment.

Technical tasks obtainable from the present invention are non-limitedthe above-mentioned technical task. And, other unmentioned technicaltasks can be clearly understood from the following description by thosehaving ordinary skill in the technical field to which the presentinvention pertains.

Technical Solution

To achieve these and other advantages and in accordance with the purposeof the present invention, as embodied and broadly described, a method ofobtaining carrier configuration information, which is obtained by amobile station in a multicarrier supportive broadband wireless accesssystem, according to one embodiment of the present invention may includethe steps of sending a 1^(st) message containing a change count value ofthe carrier configuration information retained by the mobile station toa base station, receiving a 2^(nd) message containing a current changecount value of the carrier configuration information from the basestation in response to the 1^(st) message, and if the change count valueof the 1^(st) message and the current change count value of the 2^(nd)message are different from each other, receiving a 3^(rd) messagecontaining a current carrier configuration information and the currentchange count value from the base station.

Preferably, the change count value of the 1^(st) message may include achange count value of the 3^(rd) message recently received by the mobilestation or a preset value indicating that the mobile station did notreceive the 3^(rd) message previously.

Preferably, if the change count value of the 1^(st) message and thecurrent change count value of the 2^(nd) message are different from eachother, the mobile station does not perform a multicarrier relatedoperation until receiving the 3^(rd) message.

To further achieve these and other advantages and in accordance with thepurpose of the present invention, a method of transmitting carrierconfiguration information, which is transmitted to a mobile station by abase station in a multicarrier supportive broadband wireless accesssystem, according to one embodiment of the present invention may includethe steps of receiving a 1^(st) message containing a change count valueof the carrier configuration information retained by the mobile stationfrom the mobile station, comparing the change count value of the 1^(st)message and a current change count value of the carrier configurationinformation with each other, if the change count value of the 1^(st)message and the current change count value of the carrier configurationinformation are different from each other as a result of the comparingstep, sending a 2^(nd) message containing the current change count valueto the mobile station in response to the 1^(st) message, andtransmitting a 3^(rd) message containing a current carrier configurationinformation and the current change count value to the mobile station.

Preferably, the change count value of the 1^(st) message may include achange count value of the 3^(rd) message recently received by the mobilestation or a preset value indicating that the mobile station did notreceive the 3^(rd) message previously.

Preferably, if the change count value of the 1^(st) message and thechange count value of the 2^(nd) message are different from each other,the mobile station does not perform a multicarrier related operationuntil receiving the 3^(rd) message.

To further achieve these and other advantages and in accordance with thepurpose of the present invention, a mobile station, which operates in amulticarrier supportive broadband wireless access system, according toanother embodiment of the present invention may include a processor andan RF (radio frequency) module configured to transceiver radio signalsexternally under a control of the processor, the processor controllingthe RF module to send a 1^(st) message containing a change count valueof the carrier configuration information retained by the mobile stationto a base station, the processor controlling the RF module to receive a2^(nd message containing a current change count value of the carrier configuration information from the base station in response to the)1^(st) message, the processor, if the change count value of the 1^(st)message and the change count value of the 2^(nd) message are differentfrom each other, controlling a current carrier configuration informationand the current change count value to be obtained via a 3^(rd) messagereceived from the base station.

Preferably, the change count value of the 1^(st) message may include achange count value of the 3^(rd) message recently received by the mobilestation or a preset value indicating that the mobile station did notreceive the 3^(rd) message previously.

Preferably, if the change count value of the 1^(st) message and thechange count value of the 2^(nd) message are different from each other,the processor controls a multicarrier related operation not to beperformed until receiving the 3^(rd) message.

Preferably, according to the above-mentioned embodiments, the carrierconfiguration information may include configuration information of atleast one carrier group globally applied to a network having the basestation belong thereto.

Preferably, according to the above-mentioned embodiments, the 1^(st)message may include a registration request (AAI_REG-REQ) message, the2^(nd) message may include a registration response (AAI_REG-RSP)message, the 3^(rd) message may include a global carrier configuration(AAI_Global-CFG) message, and the change count may include a globalcarrier configuration change count.

Advantageous Effects

Accordingly, the present invention may provide the following effectsand/or features.

First of all, using embodiments of the present invention, a mobilestation is able to efficiently obtain broadband carrier configurationinformation from a base station.

Secondly, a mobile station is able to know whether carrier configurationinformation contained by it is the latest through embodiments of thepresent invention, thereby preventing a multicarrier related operationfrom being performed using non-updated carrier configurationinformation.

Effects obtainable from the present invention may be non-limited by theabove mentioned effect. And, other unmentioned effects can be clearlyunderstood from the following description by those having ordinary skillin the technical field to which the present invention pertains.

DESCRIPTION OF DRAWINGS

FIG. 1( a) and FIG. 1( b) are diagrams to describe a multi-band radiofrequency (RF) based signal transceiving method.

FIG. 2 a diagram for one example of illustrating how multiple carriersare used in a general wireless communication system.

FIG. 3 is a diagram for one example of a procedure for a base station toassign at least one carrier to a mobile station in a broadband wirelessaccess system.

FIG. 4 is a diagram for one example of a procedure for updating globalcarrier configuration information via a global carrier configurationmessage according to the present invention.

FIG. 5 is a block diagram for one example of structures of transmitterand receiver according to another embodiment of the present invention.

MODE FOR INVENTION

The present invention relates to a wireless access system. In thefollowing description, methods of updating multicarrier informationefficiently according to embodiments of the present invention aredescribed.

First of all, the following embodiments correspond to combinations ofelements and features of the present invention in prescribed forms. And,it is able to consider that the respective elements or features areselective unless they are explicitly mentioned. Each of the elements orfeatures can be implemented in a form failing to be combined with otherelements or features. Moreover, it is able to implement an embodiment ofthe present invention by combining elements and/or features together inpart. A sequence of operations explained for each embodiment of thepresent invention can be modified. Some configurations or features ofone embodiment can be included in another embodiment or can besubstituted for corresponding configurations or features of anotherembodiment.

In the description of drawings, procedures or steps, which may ruin thesubstance of the present invention, are not explained. And, proceduresor steps, which can be understood by those skilled in the art, are notexplained as well.

In this specification, embodiments of the present invention aredescribed centering on the data transmission/reception relations betweena base station and a terminal. In this case, the base station ismeaningful as a terminal node of a network which directly performscommunication with the terminal. In this disclosure, a specificoperation explained as performed by a base station can be occasionallyperformed by an upper node of the base station.

In particular, in a network constructed with a plurality of networknodes including a base station, it is apparent that various operationsperformed for communication with a terminal can be performed by a basestation or other networks except the base station. In this case, ‘basestation’ can be replaced by such a terminology as a fixed station, aNode B, an eNode B (eNB), an advanced base station (ABS), an accesspoint, an advanced base station (ABS) and the like. And, ‘mobile station(MS)’ can be replaced by such a terminology as a user equipment (UE), asubscriber station (SS), a mobile subscriber station (MSS), an advancedmobile station (AMS), a mobile terminal and the like.

Moreover, a transmitter means a node that transmits a data service or aspeech service. And, a receiver means a node that receives a dataservice or a speech service. Hence, a mobile station can become atransmitter and a base station can become a receiver, in uplink.Likewise, a mobile station becomes a receiver and a base station becomesa transmitter, in downlink.

Meanwhile, a mobile terminal of the present invention may include one ofa PDA (personal digital assistant (PDA), a cellular phone, a PCS(personal communication service) phone, a GSM (global system for mobile)phone, a WCDMA (wideband CDMA) phone, an MBS (mobile broadband system)phone and the like.

Embodiments of the present invention can be implemented using variousmeans. For instance, embodiments of the present invention can beimplemented using hardware, firmware, software and/or any combinationsthereof.

In case of the implementation by hardware, a method according to eachembodiment of the present invention can be implemented by at least oneselected from the group consisting of ASICs (application specificintegrated circuits), DSPs (digital signal processors), DSPDs (digitalsignal processing devices), PLDs (programmable logic devices), FPGAs(field programmable gate arrays), processor, controller,microcontroller, microprocessor and the like.

In case of the implementation by firmware or software, a methodaccording to each embodiment of the present invention can be implementedby modules, procedures, and/or functions for performing theabove-explained functions or operations. Software code is stored in amemory unit and is then drivable by a processor. The memory unit isprovided within or outside the processor to exchange data with theprocessor through the means well-known to the public.

Embodiments of the present invention are supportable by standarddocuments disclosed in at least one of wireless access systems includingIEEE 802 system, 3GPP system, 3GPP LTE system and 3GPP2 system. Inparticular, the steps or parts, which are not explained to clearlyreveal the technical idea of the present invention, in the embodimentsof the present invention can be supported by the above documents. Inparticular, embodiments of the present invention may be supported by atleast one of P802.16-2004, P802.16e-2005, P802.16Rev2 and P802.16mdocuments which are the standards of IEEE 802.16 system.

In the following description, specific terminologies used forembodiments of the present invention are provided to help theunderstanding of the present invention. And, the use of the specificterminology can be modified into another form within the scope of thetechnical idea of the present invention.

The present specification is described on the assumption of IEEE 802.16system. In particular, a mobile station mentioned in the followingdescription may be assumed as an AMS (advanced mobile station) thatsatisfies the standards defined by IEEE 802.16m. And, a base station isassumed as an ABS (advanced base station) that satisfies the samestandards.

Terminologies usable for a multicarrier operation are defined asfollows.

1. Available carriers mean all carriers belonging to a base station(e.g., ABS). A mobile station may be able to obtain information on theavailable carrier via a global carrier configuration (AAI_Global-config)message or a multicarrier advertisement (AAI_MC-ADV) message.

2. Assigned carriers mean a subset of available carriers assigned to amobile station by a base station in accordance with capability of themobile station. In particular, in consideration of the capability of themobile station, the base station may be able to assign at least one ofits available carriers as an assigned secondary carrier of the mobilestation.

3. Active carrier means a carrier ready to actually exchange databetween a mobile station and a base station and may include a subset ofassigned carriers. Activation or deactivation of the assigned secondarycarrier may be determined by a determination of the base station basedon a QoS (quality of service) request. The base station may be able toinform the mobile station of a presence or non-presence ofactivation/deactivation of a specific secondary carrier via a carriermanagement command (AAI_CM-CMD) message.

Based on the above-mentioned definitions, a procedure for a base stationto assign a carrier to a mobile station is described with reference toFIG. 3 as follows.

FIG. 3 is a diagram for one example of a procedure for a base station toassign at least one carrier to a mobile station in a broadband wirelessaccess system.

Referring to FIG. 3, an Advanced Mobile Station (AMS) performs aninitial access procedure (e.g., an initial network entry) including ascanning step, a ranging step and the like on a base station (ABS)[S301].

The mobile station and the base station may be able to exchangeinformation on mutual multicarrier capabilities via registrationrequest/response (AAI_REG-REQ/RSP) messages [S302, S303].

Having sent the AAI-REG-RSP message to the mobile station, the basestation may be able to send a global carrier configuration(AAI_Global-CFG) message [S304].

In this case, the global carrier configuration message may containinformation on all available carriers supported by a network.

The mobile station receives a multicarrier advertisement (AAI_MC-ADV)message periodically broadcasted by the base station and may be thenable to obtain the information on a multicarrier configuration of thebase station [S305].

Subsequently, using the obtained information, the mobile station may beable to make a request for a list of assigned carrier to the basestation in a manner of informing the base station of information oncarriers (i.e., AMS's supportable carriers) supportable by the mobilestation in accordance with the multicarrier configurations of theavailable carriers of the base station via a multicarrier request(AAI_MC-REQ) message [S306].

Based on the information received from the mobile station, the basestation determines an assigned carrier list by determining a subset toassign secondary carriers of the mobile station in its availablecarriers and may be then able to inform the mobile station of thedetermined assigned carrier list via a multicarrier response(AAI_MC-RSP) message [S307].

Thereafter, the base station may be able to inform the mobile station ofa presence or non-presence of activation/deactivation of the assignedcarrier having been assigned to the mobile station in accordance withthe determination on the basis of a QoS (quality of service) request ina manner of sending a carrier management command (AAI_CM-CMD) message tothe mobile station [S308].

As mentioned in the forgoing description, multicarrier configuration(MC) information on all available carriers supported by the network incontained in the global carrier configuration message.

The multicarrier configuration (MC) information contained in the globalcarrier configuration message may include a field for the number ofcarrier group[s indicating the number of groups, in each of whichcarriers configured with subcarriers are aligned with a prescribedfrequency offset, information on each of the groups, carrier informationin the corresponding group and the like. The group information mayinclude a multiplexing mode, the number of carriers, a multicarrierconfiguration index and the like. And, the carrier information mayinclude a center frequency, a physical carrier index, a carrier type, astart frequency information and the like. Yet, this multicarrierconfiguration information of the network corresponds to a systeminformation which is very static.

Thus, if the mobile station receives the multicarrier configurationinformation from the corresponding base station each time performing anetwork entry/reentry, it may cause a problem of inefficiency. In orderto solve this problem, according to the present invention, in aregistration step of a network entry/reentry procedure, i.e., inAAI_REG-REQ/RSP message exchanging step, a mobile station informs a basestation of a global carrier configuration information retained by themobile station. If the global carrier configuration information is notvalid (i.e., if an update is necessary), the base station is proposed tosend a global carrier configuration message to the mobile station.Moreover, according to the present invention, a global carrierconfiguration change count is proposed to be used as a method ofdetermining whether to update the global carrier configurationinformation.

A global carrier configuration change count of the present invention maybe incremented by 1 each time a global carrier configuration informationis changed. And, the global carrier configuration change count iscontained in a global carrier configuration message to indicate whetherthe global carrier configuration information contained in thecorresponding message is changed. Moreover, since the global carrierconfiguration change count is contained in a registration requestmessage, a base station may be able to determine whether the globalcarrier configuration information retained by the mobile station is thelatest. On the other hand, the global carrier configuration change countis contained in a registration response message to inform the mobilestation whether a current global carrier configuration information hasbeen changed.

In the following description, a method of obtaining/updating globalcarrier configuration information using the above-described globalcarrier configuration change count is explained with reference to FIG.4.

FIG. 4 is a diagram for one example of a procedure for updating globalcarrier configuration information via a global carrier configurationmessage according to the present invention.

Referring to FIG. 4, a mobile station initiates an initial network entryor reentry such as a scanning, a ranging and the like into a basestation [S401].

In order to perform a registration procedure, the mobile station sends aregistration request (AAI_REG-REQ) message to the base station [S402].In this case, the registration request message may contain a globalcarrier configuration change count information retained by the mobilestation, i.e., a global carrier configuration change count informationof a last received global carrier configuration message lately receivedby the mobile station.

In case that the mobile station performs the initial network entry,since there will be no global carrier configuration change countinformation previously obtained, a change count value may be set to aspecific value (e.g., 0) set previously. In this case, it may bepreferable that the specific value is not used as a global carrierconfiguration change count value of a global carrier configuration(AAI_Global-CFG) message. For instance, if a change count field isconfigured with 3 bits, a value of the field may be set to a valueranging between 0 and 7. In this case, if the specific value is set to0, a change count field of the AAI_REG-RSP or AAI_Global-CFG message maybe set to a value ranging between 1 and 7 depending on a presence ornon-presence of change.

Moreover, in case that a mobile station has not received a globalcarrier configuration message at all, it may be able to use a method ofomitting a global carrier configuration change count field from aregistration request message. Moreover, it may be able to use a 1-bitinformation in a registration request message, e.g., an indication flagfield, an indication bit filed and the lie to indicate whether a globalcarrier configuration message was previously received.

Table 1 shows one example of a portion of a format of a registrationrequest message containing a global carrier configuration change countvalue.

TABLE 1 name value . . . . . . Host Host This field indicatesconfiguration configuration whether a mobile capabilities capabilitystation supports host and parameters indicator configuration usinginformation parameters received element (IE) via a registration responsemessage. If a requested host configuration IE is contained in thismessage, this field is omitted. Requested host A requested hostconfiguration configuration option IE is contained in DHCP optionformat. If contained, this information element supports a hostconfiguration by a mobile station using a registration response messageand indicates that a host configuration capability indicator IE isomitted. Global carrier configuration This field indicates change count(3 bits) a global carrier configuration change count value last receivedby a mobile station in a network. If set to 0, this field indicates thatthe mobile station has never received global carrier configurationinformation. . . .

The base station compares a global carrier configuration change countvalue of the registration request message received from the mobilestation to a current global carrier configuration change count value. Ifthere is a difference between the values compared to each other (i.e.,the global carrier configuration information of the mobile station isnot valid), the base station has the current global carrierconfiguration change count value contained in a registration responsemessage and then sends the registration response message to the mobilestation [S403]. In doing so, instead of having the current globalcarrier configuration change count value contained in the registrationresponse message, the base station may have a mismatch indicatorcontained in the registration response message to indicate that theglobal carrier configuration change count value is different/invalid.

Table 2 shows one example of a portion of a format of a registrationresponse message containing a global carrier configuration change countvalue.

TABLE 2 name Value . . . . . . Host IPv4-Host-Adress IPv4 host addressconfiguration IE assigned to UE capabilities and IPv6-Home- IPv6 hostnetwork its parameters Network-Prefix prefix assigned to IE UEAdditional-Host- Additional host Configurations configuration IE optionof DHCP option format contained Redirection Info ABSID, preambleTransmitted for index and center cell reselection frequency for inserving base one or more station in case of neighbor ABS occurrence ofan event for the serving base station not to grant an entry of a mobilestation Global carrier Indicating a configuration current value ofchange count [3 a global carrier bits] configuration change count of anetwork

If the global carrier configuration change count value retained by themobile station is different from the current value, the base stationsends a global carrier configuration message containing the latestglobal carrier configuration information by unicast to the mobilestation [S404].

Table 3 shows one example of a global carrier configuration(AAI_Global-CFG) message format containing a global carrierconfiguration change count value.

TABLE 3 Size field (bits) Description MAC Control 8 Message Type Globalcarrier 3 This field indicates a configuration value of a global carrierchange count configuration change count of a network. Number of Carrier4 This field indicates the Groups number of groups of contiguouscarriers . . . . . . . . .

In this case, the base station may be able to set a polling bit of a MACcontrol extension header (MCEH) of a medium access control protocol dataunit (MAC PDU) containing the global carrier configuration message. Inthis case, the base station may be able to inform the base stationwhether the global carrier configuration message is successfullyreceived using a message acknowledgement (AAI_MSG-ACK) message [notshown in the drawing]. If the base station fails to receive the messageacknowledgment message from the mobile station until the expiration ofan ACK timer corresponding to a time expectedly taken to receive themessage ACK message, the base station sends the global carrierconfiguration message to the mobile station again.

Having received the global carrier configuration message successfully,the mobile station performs a general data exchange with the basestation or may be able to perform a multicarrier related operation thatrequires the global carrier configuration information contained in theglobal carrier configuration message.

If the global carrier configuration change count value contained in theregistration response message is different from the global carrierconfiguration change count value of the mobile station, it may bepreferable for the mobile station not to perform the global carrierconfiguration information required operation (e.g., multicarrierassignment request using AAI_MC-REQ message, etc.) until the globalcarrier configuration message is normally received from the basestation.

Structures of Mobile station And Base Station

In the following description, a mobile station and a base station (FBS,MBS), to which the above-described embodiments of the present inventionare applicable, according to another embodiment of the present inventionare explained.

First of all, a mobile station works as a transmitter in uplink and isable to work as a receiver in downlink. A base station works as areceiver in uplink and is able to work as a transmitter in downlink. Inparticular, each of the mobile station and the base station includes atransmitter and a receiver for transmission of information and/or data.

Each of the transmitter and the receiver can include a processor, amodule, a part and/pr a means for performing embodiments of the presentinvention. In particular, each of the transmitter and the receiver caninclude a module (means) for encrypting a message, a module forinterpreting the encrypted message, an antenna for transceiving themessage and the like. Examples of the transmitter and receiver aredescribed with reference to FIG. 5 as follows.

FIG. 5 is a block diagram for one example of structures of transmitterand receiver according to another embodiment of the present invention.

Referring to FIG. 5, a left part of the drawing shows a structure of atransmitter and a right part of the drawing shows a structure of areceiver. The transmitting/receiver may include an antenna 5/10, aprocessor 20/30, a transmitting (Tx) module 40/50, a receiving (Rx)module 60/70 and a memory 80/90. And, the respective components may beable to perform functions corresponding to each other. The respectivecomponents are described in detail as follows.

The antenna 5/10 performs a function of externally transmitting a signalgenerated from the transmitting module 40/50 or a function of receivinga radio signal from outside and then delivering the received radiosignal to the receiving module 60/70. In case that a multiple-antenna(MIMO) function is supported, at least two antennas can be provided tothe mobile station or the base station.

The antenna, the transmitting module and the receiving module may beintegrated into a radio frequency (RF) module.

The processor 20/30 generally controls overall operations of amobile/base station. In particular, the processor 20/30 is able toperform a control function for performing the above-describedembodiments of the present invention, a MAC (medium access control)frame variable control function according to service characteristics andpropagation environment, a handover function, an authenticationfunction, an encryption function and the like. In more particular, theprocessor 20/30 can further perform overall controls for the carrierconfiguration information obtaining/updating procedure.

Especially, the processor of the mobile station may be able to determinewhether the global carrier configuration information retained by themobile station is valid in the base station through a registrationrequest/response message exchange in the course of an initial networkentry/reentry. The determination of the validation may be performed in amanner of comparison of a global carrier configuration change countvalue of the registration request/response message.

If the global carrier configuration information is not valid, the mobilestation is able to receive a global carrier configuration message byunicast from the base station. If MAC PDU for carrying the correspondingmessage is accompanied by MCEH having a polling bit set to 1, the mobilestation may be able to inform the base station whether the globalcarrier configuration message is successfully received using AAI_MSG-ACKmessage.

In case that the base station performs an initial network entry, sincethere is no AAI_Global-CFG message previously received, the mobilestation may be able to send a registration request message in a mannerof setting a global carrier configuration change count to a predefinedvalue (e.g., 0) in the registration request message.

Besides, the processor of the mobile station may be able to performoverall control operations of the operating process disclosed in theabove-mentioned embodiments.

The transmitting module 40/50 performs prescribed coding and modulationon a data, which is scheduled by the processor and will be thentransmitted externally, and is then able to deliver the coded andmodulated data to the antenna 50/10.

The receiving module 60/70 reconstructs the radio signal receivedexternally via the antenna 1000/1010 into original data in a manner ofperforming decoding and demodulation on the radio signal received viathe antenna 5/10 and is then able to deliver the reconstructed originaldata to the processor 20/30.

The memory 80/90 can store programs for processing and control of theprocessor 20/30 and is able to perform a function of temporarily storinginput/output data. And, the memory 80/90 can include at least one ofstorage media including a flash memory, a hard disk, a multimedia cardmicro type memory, a memory card type memory (e.g., SD memory, XDmemory, etc.), a RAM (random access memory), an SRAM (static randomaccess memory), a ROM (read-only memory), an EEPROM (electricallyerasable programmable read-only memory), a PROM (programmable read-onlymemory), a magnetic memory, a magnetic disk, an optical disk and thelike.

Meanwhile, the base station may perform a controller function forperforming the above-described embodiments of the present invention, anOFDMA (orthogonal frequency division multiple access) packet scheduling,TDD (time division duplex) packet scheduling and channel multiplexingfunction, a MAC (medium access control) frame variable control functionaccording to a service characteristic and electric wave environment, afast traffic real-time control function, a handover function, anauthentication and encryption function, a packet modulation/demodulationfunction for data transmission, a fast packet channel coding function, areal-time modem control function, and the like using at least one of themodules mentioned in the foregoing description and may further includemeans, modules, parts and/or the like to perform these functions.

While the present invention has been described and illustrated hereinwith reference to the preferred embodiments thereof, it will be apparentto those skilled in the art that various modifications and variationscan be made therein without departing from the spirit and scope of theinvention. Thus, it is intended that the present invention covers themodifications and variations of this invention that come within thescope of the appended claims and their equivalents. And, it isapparently understandable that an embodiment is configured by combiningclaims failing to have relation of explicit citation in the appendedclaims together or can be included as new claims by amendment afterfiling an application.

INDUSTRIAL APPLICABILITY

Accordingly, a more efficient broadband carrier configurationinformation obtaining/updating procedure in a broadband wireless accesssystem and a device structure for the same are mainly described bytaking one example applied to IEEE 802.16m system and may be furtherapplicable to various kinds of mobile communication systems including3GPP/3GPP2 and the like as well as IEEE 802.xx system.

1. A method of obtaining carrier configuration information carried outby a mobile station in a broadband wireless access system supportingMulti-carrier, the method comprising: transmitting a 1^(st) messageincluding a change count value of the carrier configuration informationretained by the mobile station to a base station; obtaining a currentchange count value included in a 2^(nd) message received from the basestation in response to the 1^(st) message; and if the obtained changecount value becomes invalid after receiving the 2^(nd) message,receiving a 3^(rd) message including a current carrier configurationinformation and a currently valid change count value from the basestation.
 2. The method of claim 1, wherein the carrier configurationinformation comprises configuration information of at least one carriergroup globally applied to a network having the base station belongthereto.
 3. The method of claim 1, wherein the change count value of the1^(st) message comprises a change count value of a latest received3^(rd) message or a preset value indicating that the mobile station didnot receive any 3^(rd) message previously.
 4. The method of claim 1,wherein if the change count value obtained by the mobile station isinvalid, the mobile station does not perform a multicarrier relatedoperation until receiving the 3^(rd) message.
 5. The method of claim 1,wherein the 1^(st) message comprises a registration request(AAI_REG-REQ) message, wherein the 2^(nd) message comprises aregistration response (AAI_REG-RSP) message, wherein the 3^(rd) messagecomprises a global carrier configuration (AAI_Global-CFG) message, andwherein the change count comprises a global carrier configuration changecount.
 6. A method of transmitting carrier configuration information toa mobile station carried out by a base station in a broadband wirelessaccess system supporting Multi-carrier, the method comprising: receivinga 1^(st) message including a change count value of the carrierconfiguration information retained by the mobile station from the mobilestation; checking whether the change count value of the 1^(st) messageis valid or not; if the change count value of the 1^(st) message isinvalid, transmitting a 2^(nd) message including the current changecount value to the mobile station in response to the 1^(st) message; andif the change count value obtained by the mobile station is invalidafter transmitting the 2^(nd) message, transmitting a 3^(rd) messageincluding a current carrier configuration information and a currentlyvalid change count value to the mobile station.
 7. The method of claim6, wherein the carrier configuration information comprises configurationinformation of at least one carrier group globally applied to a networkhaving the base station belong thereto.
 8. The method of claim 6,wherein the change count value of the 1^(st) message comprises a changecount value of a latest 3^(rd) message received by the mobile station ora preset value indicating that the mobile station did not receive any3^(rd) message previously.
 9. The method of claim 6, wherein if thechange count value obtained by the mobile station is invalid, the mobilestation does not perform a multicarrier related operation untilreceiving the 3^(rd) message.
 10. The method of claim 6, wherein the1^(st) message comprises a registration request (AAI_REG-REQ) message,wherein the 2^(nd) message comprises a registration response(AAI_REG-RSP) message, wherein the 3^(rd) message comprises a globalcarrier configuration (AAI_Global-CFG) message, and wherein the changecount comprises a global carrier configuration change count.
 11. Amobile station, which operates in a multicarrier supportive broadbandwireless access system, comprising: a processor; and an RF (radiofrequency) module configured to transceiver radio signals externallyunder a control of the processor, wherein the processor is configuredto: transmit a 1^(st) message including a change count value of thecarrier configuration information retained by the mobile station to abase station, obtain a current change count value included in a 2^(nd)message received from the base station in response to the 1^(st)message, and if the obtained change count becomes invalid afterreceiving the 2^(nd) message, receive a 3^(rd) message including acurrent carrier configuration information and the currently valid changecount value from the base station.
 12. The mobile station of claim 11,wherein the carrier configuration information comprises configurationinformation of at least one carrier group globally applied to a networkhaving the base station belong thereto.
 13. The mobile station of claim11, wherein the change count value of the 1^(st) message comprises achange count value of a latest 3^(rd) message received by the mobilestation or a preset value indicating that the mobile station did notreceive the 3^(rd) message previously.
 14. The mobile station of claim11, wherein if the change count value obtained by the mobile station isinvalid, the processor controls a mutt carrier related operation not tobe performed until receiving the 3^(rd) message.
 15. The mobile stationof claim 11, wherein the 1^(st) message comprises a registration request(AAI_REG-REQ) message, wherein the 2^(nd) message comprises aregistration response (AAI_REG-RSP) message, wherein the 3^(rd) messagecomprises a global carrier configuration (AAI_Global-CFG) message, andwherein the change count comprises a global carrier configuration changecount.